1. Field of the Invention
This invention relates to novel electromechanical transducer devices for relief display panels, to methods of using these and to equipment incorporating them.
The invention relates generally to reading and monitoring apparatus for the blind and more particularly to methods and devices for converting data into and/or from tactual symbols, such as Braille.
Electronic pocket calculators could be of immense service to the blind who encounter the greatest difficulty in making numerical calculations, especially when these calculations require the use of magnitudes which must be sought in tables (for example logarithms, trigonometric functions, etc.).
Such calculators are at present useless to blind persons since the results are presented in the form of a visual image e.g. luminous figures in a window.
In the Braille system, each sign (letter, figure or sign of punctuation) is represented by a geometric figure constituted of points in relief to a maximum number of six. These geometric figures are easily recognized to the touch by the blind who can, with training, read very rapidly. Unfortunately, braille books are heavy, bulky and expensive to produce, which limits the access of blind people to written information.
2. Description of the Prior Art
To overcome these drawbacks and to produce texts in relief from electrical signals, electromechanical methods are known enabling the production of Braille characters in relief. The known methods have all numerous drawbacks: mechanical complexity, bulk, weight, noise, high consumption of electricity.
More recently, it has been proposed to use vibrating points with piezoelectric actuation to constitute characters intended to be read by touch (U.S. Pat. No. 3,229,387). This device has, however, serious drawbacks. Firstly, the majority of blind people find their sense of touch fatigued and even irritated by the vibrations. Furthermore, they are obliged to adapt themselves to a mode of reading which is very different from that of books in relief: instead of drawing the finger over a line of characters in relief, thereby being able to slow down, accelerate, stop or back-track at will, they must--by reason also of fragility of the vibrating points--leave the finger immobile on the vibrating points, the latter then successively presenting the characters of the text. Lastly, the vibrating points emit a distinctly audible sound, which then constitutes a nuisance in the vicinity particularly if several persons work close together.